TCP chokes between Ultrix 4 and 3.1c systems

[Ian! D. Allen [CGL]]

>Yet another amusing feature.  I think this may have come up quite some time
>back.  When I use ftp, telnet, or even mail to a DS3100 running Ultrix 3.1c
>from my DS5000 running Ultrix 4.0, the connection hangs whenever 512 or more
>bytes are sent from a single operation (e.g., mail messages, ftp files,
>or commands in telnet).  The same thing happens when the folks on the other
>end try to talk to me.  Neither of us have any problems talking to non-Ultrix
>systems, and I can talk to other Ultrix 4.0 systems just fine.

Aha!  We see this behaviour between real MIPS machines and our Ultrix
3.1C DECsystem 5400's.  BSD Vaxen, Suns, other machines, have no
problem talking to the 5400's, but connecitons from those three MIPS
machines hang on large packets.  And it's asymmetric -- we can rcp *out*
of the DS5400, but not in.
-- 
-IAN! (Ian! D. Allen) idallen at watcgl.uwaterloo.ca idallen at watcgl.waterloo.edu
 [129.97.128.64]  Computer Graphics Lab/University of Waterloo/Ontario/Canada